This invention relates to telecommunications terminals.
Telecommunications terminals connect subscriber lines, such as POTS (Plain Old Telephone Service) and ISDN (Integrated Services Digital Network) lines, to telecommunications exchanges and other telecommunications equipment. A terminal includes channel unit card slots that accept channel unit cards. Channel unit cards convert analog and digital signals from subscriber lines into formatted digital data signals. Different types of channel unit cards service different types of subscriber lines (e.g. POTS or ISDN). The terminal constructs a single time division multiplexed (TDM) signal from several channel unit cards' formatted digital data signals for transmission to remote telecommunications equipment. The terminal also demultiplexes TDM signals received from remote telecommunications equipment to deliver formatted digital data back to the channel unit cards which then convert the formatted digital data into a form suitable for transmission over subscriber lines.
Two telecommunications terminals can be connected "back to back" to form a digital loop carrier (DLC) network. A DLC network typically includes a remote terminal (RT) placed near a business or residence and a central terminal (CT) placed in a central exchange connected to a telecommunications switch. The RT and CT communicate over a single line carrying TDM signals. This configuration connects subscribers to the telecommunications switch.
A telecommunications terminal management system provides administrators and others with information about terminals aggregated at a site. Terminal information includes descriptions of the channel unit cards currently installed in the terminal.
A simple telecommunications terminal management system has a computer connected to a telecommunications terminal. The computer collects and displays information about the terminal. The computer can collect information by sending Transaction Language 1 (TL1) commands to the terminal. TL1 is a Bellcore language that defines different ASCII commands that telecommunications terminals can understand and process. For example, if the computer sends the terminal the TL1 command RTRV-EQUIP-ALL, the terminal would respond by sending back a TL1 ASCII message containing information describing installed equipment--namely, all of the channel unit cards presently installed in the terminal.
Administrators using DSC.TM. Communications Corporation's Liteview.TM. terminal management system manually initiated polling (e.g. sending TL1 retrieve messages) of a telecommunications terminal whenever the administrators wanted to update the system's knowledge of which cards a terminal held.